Detergent builders and compositions containing the same

ABSTRACT

Disclosed and claimed are biodegradable builders for use with water-soluble organic detergent compounds. The builders are alkali metal salts of ester-acids derived from polycarboxylic acid anhydrides.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to detergent compositions containing novel builders, to a method for making such builders, and to detergent compositions containing such builders.

2. Description of the Prior Art

Because phosphates are believed to contribute to the eutrophication of waters, considerable research efforts recently have been expended with a view of providing builders which are phosphorus free.

Phosphate-free organic builders are already known and some are disclosed in Unilever Netherlands patent application 72-06772 and in U.S. Pat. No. 3,635,830. The first of these discloses the tetrahydrate and pentahydrate of carboxymethoxysuccinate trisodium which were used separately or together as builders in detergent compositions. Undesirably, these compounds have to be treated with water-ethanol to hydrate them sufficiently to be easily handled thereby adding considerably to production costs. For its part, U.S. Pat. No. 3,635,830 discloses, as builders, salts of oxydisuccinic acid, carboxymethyloxy succinic acid and hydrofuran tetracarboxylic acid. The recited compounds required several purification steps before incorporation in detergent compositions.

SUMMARY OF THE INVENTION

The builders of the invention are the reaction products of alkali hydroxy alkyl salts with polycarboxylic acid anhydrides and can be represented by the following general formula: ##STR1## WHEREIN X is ##STR2## R being hydrogen, alkyl, aryl or repeating X unit; M is an alkali metal cation including sodium, potassium, lithium or ammonium; and Y is (CH₂)_(n) COOM or (CH₂)_(n) SO₃ M wherein n ranges from 1 to 6 and M is as before defined.

The starting materials are alkali hydroxy salts of the formula:

    HO(CH.sub.2).sub.n COOM

or

    HO(CH.sub.2).sub.n SO.sub.3 M

n and M being as defined before and;

Polycarboxylic acid anhydrides of the formula: ##STR3## X being as defined above.

The reaction is carried out in the absence of solvent or in polar solvents which are inert to the anhydride including dioxane, dimethylformamide and methyl ethyl ketone. The reaction is carried out at temperatures of 25°-250° C. and atmospheric pressure to 1000 psi with the preferred conditions being 75°-150° C. and atmospheric pressure to 100 psi.

For sake of simplicity the invention will be described mainly with reference to sodium carboxymethyl maleate (SCMM) which is prepared by the reaction of maleic anhydride with sodium glycolate wherein the addition is across the anhydride and apparently is followed by a neutralization step where the sodium glycolate or the adduct is the base: ##STR4##

Experimental conditions are summarized in Table I. The ingredients were mixed and heated for the time indicated and worked up as outlined. In addition to small amounts of starting materials which contaminated the products, other fractions, not listed, appeared to be principally recovered starting material but in one or two cases were possibly mixed with acid or salt precursors of sodium carboxymethyloxy succinate (SCMS). ##STR5##

The crude sodium carboxymethyl maleate was purified from acetone, methyl ethyl ketone and/or methanol. The product was identified by nuclear magnetic resonance spectra as indicated in Table II, a quartet in the olefin region and a singlet in the ##STR6## region but shifted from the singlet for sodium glycolate. The unpurified samples also showed spectra for both maleic anhydride and sodium glycolate in varying amounts.

Sodium analyses given in Table II indicated that reactions according to Equations 2 and 3 above, probably took place.

Sample P698-31Sl was prepared by treatment with sodium methoxide assuming only Equation 1 had occurred. However, sodium analyses were little different with samples obtained without sodium methoxide neutralization and agree with the theoretical sodium content of the di-salt rather than the mono-salt (%Na=11.7).

                                      TABLE I                                      __________________________________________________________________________     PREPARATION OF SODIUM CARBOXYMETHYL MALEATE (SCMM)                             __________________________________________________________________________     Maleic                                                                               Sodium                 Reaction Conditions                                                                              Crude                           anhydride,                                                                           Glycolate                                                                            Solvent  Catalyst                                                                               Temp.                                                                              Time          SCMM   Run                      gms   gms.  Name  Ml.                                                                               Name gms.                                                                              ° C.                                                                        hrs.                                                                              Work-up    gms.   No.                      __________________________________________________________________________     10    10    Dioxane                                                                              100                                                                               Benzoyl                                                                             0.1                                                                               70  24 cooled, filtered                                                                          14.4   (875-34)                                      peroxide                  (50%)                           10    10    Dimethyl                                                                             100                                                                               Benzoyl                                                                             0.1                                                                               70  24 cooled, filtered                                                                          12     C875-41                              formamide                                                                               peroxide                  (50%)                           10    10    None  -- None -- 80-128                                                                             1/2                                                                               cooled, extract-                                                                          13.5   C875-41                                                      ed with acetone.                                                                          (50%)                                                               Insoluble extrac-                                                              ted with methanol.                                                             Part of methanol                                                               solution treated                                                               with sodium meth-                                                              oxide.                                     20    20    None  -- None -- 100  1 cooled, extract-                                                                          18.8   P113-7                                                       ed with methanol.                                                                         (70%)                           10    10    Methyl                                                                               200                                                                               None -- Reflux                                                                             24 cooled, extracted                                                                         10.6   P113-8                               ethyl                   MEK-insoluble with                                                                        (90%)                                       ketone                  methanol   (MEK-CH.sub.3 OH                                                               insoluble)                      10     9.5  methyl                                                                               200                                                                               None -- Reflux                                                                             24 cooled, filtered                                                                          (10.6  P113-11                              ethyl                              (70%)                                       ketone                             (MEK insoluble)                 Value in parenthesis is approximately purity (bais NMR) of crude               __________________________________________________________________________     SCMM                                                                      

                                      TABLE II                                     __________________________________________________________________________     EVALUATION OF SODIUM CARBOXYMETHYL MALEATE AND RELATED MATERIALS               __________________________________________________________________________     Material   SCMM   SCMM    SCMM         STPP.sup.(2)                                                                        Maleic                                                                               Sodium                                                                              Sodium                  Test       Sample 1                                                                              Sample 2.sup.(a)                                                                       Sample 3                                                                              SCMS.sup.(1)                                                                         Standard                                                                            Anhydride                                                                            Maleate                                                                             Glycolate               __________________________________________________________________________     Proton NMR δ5.8-6.8                                                                        δ5.8-6.7                                                                         δ5.8-6.7                                                                        δ4.0-4.2                                                                       --   δ6.7 (s2)                                                                      δ6.5                                                                          δ4.0 (s2)         (in D.sub.2 O)                                                                            (q2)   (q2)    (q2)   (m1)                                                     δ4.45 (s2)                                                                      δ4.5                                                                             δ4.5                                                                            δ3.9                                                      (s2)    (s2)                                                                                  δ2.4-                                                                    2.6                                                                            (m2)                                          Sodium % (Found)                                                                          19.9   19.8    21.7   20.9  --   --    --   --                           (theory)                                                                             21     21      21     19.8  --   --    --   --                                                       (Hydrated)                                    Sap. No. (Found)                                                                          --     --      257.8  --    --   --    --   --                           (theory)                                                                             --     --      257    --    --   1150  0    0                       Neut. No. (Found)                                                                         --     --      14.3   --    --   --    --   --                           (theory)                                                                             --     --      0      --    --   1150  0    0                       Detergency --     89.2    85.2   89.7  100  --    --   --                      Coefficient, %                                                                 Identification                                                                            P698-31S1                                                                             P113-7A P113-10S+                                                                             P113- --   --    --   --                      No.                       11S    30S2                                          __________________________________________________________________________      .sup.(1) Made according to Netherlands application 701 7130                    .sup.(2) Sodium tripolyphosphate                                               .sup.(a) Also contained singlets at δ4. and δ6.3 due to sodiu      glycolate and sodium acetate                                             

Detergency values compared to sodium tripolyphosphate were obtained with test fabric cotton in a Launder-Ometer test using detergent solutions made up with hard water and a commercial Naccanol (LABS) surfactant.

In the test procedure used standard wash solutions are prepared with detergent contents of 0.1, 0.1, 0.2 and 0.2% in about 3000 ppm hard water. The detergent composition is a 70/30 by weight mixture of builder (either STPP, SCMS or the ester-salt) and Nacconol 90F. The hard water was previously prepared by dissolving 26.43 grams CaCl₂.2H₂ O in 600 ml of distilled water and mixing this solution with a solution of 29.58 grams of Mg SO₄ . 7H₂ O in 600 ml of distilled water and making the admixed solutions up to 10 liters with distilled water.

Standard soiled cloths containing the same amount of soil are placed in each solution and washed in a Launder-Ometer (1) for 10 minutes at 60° C. The cloths are removed from the wash solutions, rinsed, dried and the degree of whiteness measured by a Photovolt Reflectometer (2). The degree of whiteness of both soiled unwashed cloth and unsoiled unwashed cloth is also measured. The reflectance values from the washed soiled cloths obtained from both the 0.1 and 0.2% detergent solutions are averaged and the percent Detergency calculated:

Rsu = reflectance of soiled unwashed cloth

Ruu = reflectance of unsoiled unwashed cloth

The Detergency Coefficient is then calculated from the detergency of the test-salt and sodium tripolyphosphate: ##EQU2## (Standard = sodium tripolyphosphate)

Values of Detergency Coefficients obtained are given in Tables II and IV. It is noteworthy to remark that the sodium carboxymethyl maleate and the sodium carboxymethyl succinate are very slightly less effective than the non-biodegradable sodium tripolyphosphate.

A crude (P113-7A) and a purified material (P113-10S+11S), 95% pure SCMM were evaluated and were comparable with the patented SCMS and were very slightly below the standard (a 90% performance being considered equivalent for the present purposes).

It is important to note that the SCMM appeared less sticky than the SCMS so it apparently did not hydrate as readily. According to the literature, SCMS has to be treated with water-ethanol to completely hydrate it in order to make it more easily handled but advantageously this step is not necessary with SCMM builder of the invention.

The preparation of additional ester-salts was carried out by the reaction of other dicarboxylic acid anhydrides with sodium glycolate in methyl ethyl ketone. Experimental conditions are summarized in Table III.

Besides crude sodium carboxymethyl succinate (SCMeS, insoluble in methyl ethyl ketone) products soluble in the methyl ethyl ketone were obtained among which, basis nuclear magnetic resonance, appears to be carboxymethyl succinic acid. The crude SCMeS was contaminated with starting materials but was purified by recrystallization from acetone. The salt and the acid were characterized by nuclear magnetic resonance as indicated in Table IV, multiplets forming in the ##STR7## region and singlets in the ##STR8## region but shifted from the singlet for sodium glycolate. The sodium analyses given in Table IV confirm that reactions to form the disodium salt comparable to those in equations 2 and 3, above, probably took place.

Also, as above, detergency values compared to sodium tripolyphosphate were obtained with test fabric cotton in a Launder-Ometer test using detergent solutions made up with hard water and Naccanol 90F. As shown by data in Table IV the purified SCMeS (P360-25SA + 16 AA) was very slightly below the standard.

With the other anhydrides listed in Table III, ester-salts were obtained, but the products were not isolated. That reaction products were obtained is indicated by nuclear magnetic resonance data given in Table V. Product mixture showed spectra for starting materials as well as the spectra listed, assigned to and agreeing with the spectra for the ester-salts. In the cases of tetrahydrophthalate and hexahydrophthalate derivatives, two slightly separated singlets were obtained in the ##STR9## region due to the ##STR10## from the sodium glycolate addition. This is apparently due to the presence of isomers in the product.

                                      TABLE III                                    __________________________________________________________________________     PREPARATION OF OTHER CARBOXYMETHYL ESTER SALTS                                 ANHYDRIDE                Reaction Condition                                                                             Product                                               Sodium                                                                             Methyl-                                                                    Glyco-                                                                             ethyl-                               Amount                __________________________________________________________________________                                                              (2)                                   late                                                                               ketone,  Time.                          pur-               Name Formula gms.                                                                              gms.                                                                               ml.  Temp.                                                                              Hrs.                                                                              Work-up  Name Formula    gms.                                                                              ity                __________________________________________________________________________     Succinic anhydride                                                                   ##STR11##                                                                             10.2                                                                              10  200  Reflux                                                                             24                                                                                 ##STR12##                                                                              Sodium carboxy- methyl succinate                                               SCMeS)                                                                               ##STR13## 10.6                                                                              85                 Succinic anhydride                                                                   ##STR14##                                                                             10.2                                                                              12  200  Reflux                                                                             30 Cooled, filtered. MEK soluble recovered                                        by evaporation, wt. 7.5 gms                                                             Sodium  carboxy- methyl succinate                                               (SCMeS)                                                                             ##STR15##                       O- Phthalic anhydride                                                                ##STR16##                                                                             15.1                                                                              10  200  Reflux                                                                             24                                                                                 ##STR17##                                                                              Sodium carboxy- methyl phthalate                                               SCMP)                                                                                ##STR18## Not esti- ma-                                                                  ted                                                                               --                 cis-Δ4- tetra- hydro- phthalic anhydride (THPA)                                ##STR19##                                                                             15.5                                                                              10  200  Reflux                                                                             24                                                                                 ##STR20##                                                                              Sodium carboxy- methyl- tetra-                                                 hydro- phthalate (SCMTP)                                                             ##STR21##                       cis hexa- hydro- phathalic anhydide (HHPA)                                           ##STR22##                                                                             15.7                                                                              10  200  Reflux                                                                             24                                                                                 ##STR23##                                                                              Sodium carboxy- methyl hexa-                                                   hydro- phthalate (SCMHP)                                                             ##STR24## 4.2                                                                               --                 __________________________________________________________________________     Run No.                                                                        Succinic  P360-16                                                              anhydride                                                                      Succinnic P360-25                                                              anhydride                                                                      o-Phthalic                                                                               P360-19                                                              anhydride                                                                      cis-Δ.sup.4 -tetra-                                                                P360-17                                                              hydrophthalic                                                                  anhydride (THPA)                                                               cis-hexa-                                                                      hydro-    P360-18                                                              phthalic                                                                       anhydride                                                                      (HHPA)                                                                         __________________________________________________________________________      (1) Mixture of sodium glycolate or glycolic acid, succinic anhydride and,      apparently, carboxymethyl succinic acid                                        (2) Estimated from NMR                                                   

                                      TABLE IV                                     __________________________________________________________________________     EVALUATION OF SODIUM CARBOXYMETHYL SUCCINATE AND RELATED                       __________________________________________________________________________     MATERIALS                                                                                   SCMeS SCMeS                                                                               SCMeS                                                                              SCMeS                                              Material     Sample                                                                               Sample                                                                              Mix of                                                                             1 and 2                                                                             Succinic                                                                            Carboxymethyl                            Test          1     2   1 and 2                                                                            purified                                                                            anhydride                                                                           Succinic acid                            __________________________________________________________________________     Proton NMR (in D.sub.2 O)                                                                   δ4.45                                                                          δ4.45                                                                         --  δ4.45                                                                         δ2.6                                                                          δ4.6 (s2)                                       (s2)  (s2)     (s2) (s)  δ2.6-2.8                                        δ2.4-2.8                                                                       δ2.4-2.8                                                                          δ2.4-2.8                                                                           (m4)                                                  (m4)  (m4)     (m4)      (1)                                                   (1)   (1)                                                         Sodium, % (Found)                                                                           17.5  22.7 --  20.6 --   --                                       (theory)     20.9  20.9 --  20.9 --   --                                       (for disodium salt)                                                            Detergency Coefficient, %                                                                   --    --   81.2                                                                               89.4 --   --                                       Identification No.                                                                          P360-16A                                                                             P360-                                                                               P360-                                                                              P360-                                                                 25S  25S +                                                                              25SA +                                                                     16A 16AA                                               __________________________________________________________________________      (1)Also contained signlets at δ2.6 and δ3.9 due to succinic        anhydride or sodium succinate and sodium glycolate.                            (2)See Table II for additional comparative data on STPP (standard) and         sodium glycolate                                                         

                                      TABLE V                                      __________________________________________________________________________     NMR DATA ON DERIVATIVES OF CYCLIC ANHYDRIDES                                   __________________________________________________________________________                                       Sodium                                                           Sodium        Carboxy-                                              Sodium     Carboxy-      methyl                                                                               Hexa-                                           Carboxy-   methyl Tetrahydro-                                                                           hexa- hydro-                                 Material methyl                                                                              Phthalic                                                                             tetrahydro-                                                                           phthalic                                                                              hydro-                                                                               phthalic                                                                             Sodium                           Test     phthalate                                                                           anhydride                                                                            phthalate                                                                             anhydride                                                                             phthalate                                                                            anhydride                                                                            Glycolate                        __________________________________________________________________________     Proton NMR ( in                                                                         δ7.3-7.7                                                                      δ8.0                                                                           δ5.62-5.77                                                                      δ5.7                                                                            δ4.33-4.4                                                                      δ3.05-3.35                                                                     4.0                              D.sub.2 O)                                                                              (m4) (in CCl.sub.4)                                                                       δ(s(?))                                                                         (t-2)  (2s 2)                                                                               (m2)  (s2)                                      δ5.7 δ4.4-4.5                                                                        δ3.0-3.2                                                                        δ2.7-3.0                                                                       δ1.75-2.15                                (s2)       (2s)   (m2)   (m (mr)                                               (1)        δ2.95-3.25                                                                      δ2.3-2.7                                                                        δ1.6-2.1                                                                       δ1.4-1.75                                            (m)    (dr) (m4)                                                                             (m4) -            δ2.2-2.5  .delta                                                         .1.25-1.6                                      (t)           (m4)                                                             (2)           (1)                                          __________________________________________________________________________      (1) Product contaminated with sodium glycolate                                 (2)Product contaminated with sodium glycolate and charge anhydride       

In another embodiment of the invention, maleic anhydride was treated with sodium isethionate (sodium hydroxy ethyl sulfonate, HOCH₂ CH₂ SO₃ Na). A reaction occurred but yields were low. For example, when 10 grams maleic anhydride, 14 grams sodium isethionate and 200 ml. methyl ethyl ketone were refluxed together for 24 hours 14.4 grams of material was obtained that was a mixture of product and unreacted sodium isethionate (Basis NMR):

    ______________________________________                                                     Sodium                                                                         Sulfoethyl   Sodium                                                            Maleate      Isothionate                                           ______________________________________                                         NMR (in D.sub.2 0)                                                                           δ3.2-3.4 (t)                                                                            δ3.1-3.2 (t)                                              δ4.45-4.5 (d or t)                                                                      δ3.8-4.0 (t)                                              δ6.3-6.5 (q)                                               Estimated amount of                                                                            12           88                                                product, per cent                                                              ______________________________________                                    

Also 8.8 grams maleic anhydride, soluble in methyl ethyl ketone, was recovered.

Some sodium sulfoethyl maleate was also obtained when the reaction was run in dimethyl sulfoxide.

It will be understood that detergent compositions in which the builders of the invention are incorporated to the amount of about 5 to 95% based on the weight of the total detergent composite will include conventional compounds generally used in such formulations. The major ingredients of these compositions are surface active agents, soil suspending agents, sequestrants, foam stabilizers, alcohols, coloring materials, thickening agents and hydrotropes.

Suitable surface active agents include anionic, nonionic, zwitterionic, ampholytic surfactants and mixtures thereof, especially those normally used in the washing of laundry and other soiled articles. These are used in an amount ranging from about 5 to about 45% of the total composition.

The hydrotropes which may be used as solubilizing agents include aromatic sulfonates such as sodium and potassium xylene sulfonates. The conventional amount of hydrotrope used varies from about 1.5 to about 10 percent by weight of the detergent.

Thus a solid detergent incorporating the builders of this invention would consist, in percentage by weight of

    ______________________________________                                         Water soluble surface active agents                                                                    3.5 to 45%                                             Hydrotropes             1.5 to 10%                                             Builders of the invention                                                                                5 to 95%                                             ______________________________________                                    

A liquid detergent incorporating the builders of the invention would consist of:

    ______________________________________                                         C.sub.7 -C.sub.8 linear alkylsulfonate hydrotrope                                                      3 to 9 wt. %                                           Fatty acid alkylolamide foam stabilizer                                                                0 to 5 wt. %                                           Linear alkylsulfonate detergent (C.sub.11 -C.sub.19)                                                   5 to 10 wt. %                                          Builders of the invention                                                                             15 to 20 wt. %                                          Water                  Balance                                                 ______________________________________                                    

It is to be understood that the foregoing examples are presented by way of illustration and explanation and that the invention is not limited by the details of such examples. 

What is claimed is:
 1. A detergent builder of the formula: ##STR25## wherein M is an alkali metal cation or ammonium; and Y is (CH₂)_(n) COOM, wherein n ranges from 1-6 and M is as before defined.
 2. A detergent composition consisting essentially of 3.5 to 45 percent by weight of a water-soluble surface active agent of the group of anionic, nonionic, zwitterionic, ampholytic surfactants and mixtures thereof; 1.5 to 10 percent by weight of a hydrotrope; and from about 5 to 95 percent by weight of the total composition of a builder as defined in claim
 1. 3. The composition of claim 2, wherein said builder is sodium carboxymethyl maleate. 